Facebook just revealed that it’s testing a new feature called “Buy with Friends” for its site, which will allow users to share their deals on virtual goods — and I’m starting to wonder whether Facebook could bring something similar to non-virtual deals.

Commerce product marketing manager Deb Liu described the feature on-stage today at the Inside Social Apps InFocus conference in San Francisco. (I’m at the conference, but I was busy writing about other news, so for this story I’m relying on the coverage from Forbesand All Things Digital.) The idea is to let users tell their friends about virtual goods purchases that they’ve made in Facebook games. Most interestingly, if a user unlocks a deal, they might be able to share it with their friends.

Facebook has constantly worked to find the right balance in allowing developers to promote themselves in users’ newsfeeds without users feeling that they’re being spammed. (Chief technology officer Bret Taylor said earlier today that Facebook has reduced spam by 95 percent in the past year.) Buy With Friends offers a possible solution to that problem, because a message about a random Facebook game will probably seem much less annoying when it actually benefits you, say if it tells you, “Your friend has unlocked this deal for you — get 40 percent off this special monster food.”

More than 50 percent of users in the test program elected to share their purchases, Liu said.

Again, this is all about virtual goods for now, but it might carry over nicely into the Deals product that Facebook announced last November. Right now, businesses can offer different kinds of deals as a reward for check ins on Facebook Places. What if you could then share those deals with your friends? For example, you might win a discounted pair of jeans if you check in to Levi’s often enough, then you could offer your friends a similar discount. It would be a way for Facebook to compete with popular group-buying site Groupon in a way that doesn’t just copy Groupon’s features.